There seems to be no end to the variations available for fresh water shrimp or scud patterns. This happens to be one of my favorites for fishing on our Green River. It may be dressed in all of the traditional colors, amber, green, pink, orange, or any others that might be your favorite. I prefer to add three rubber legs out the back to simulate feelers. This is a very simple pattern to tie. The one pictured was not even dubbed. I simply used a brushed yarn and wrapped the body. You can, of course, use any dubbing that you wish. However, you should remember that not all dubbings will absorb water and unless you use a small amount of lead, your scud will float. This isn't all bad in the proper circumstance, but most of the time you will want to fish this pattern deep. I have, on occasion, used a floating scud over weed beds and fished it as a dry fly to keep it from becoming tangled. That technique works well on fish that are being very selective, or staying deep in the weeds where you can not get a good drift.
The important thing on this fly is to get the legs combed out so that the pattern does not look like a smooth football. You may use a bodkin, or any number of other tools to do this.
I prefer a small strip of Velcro as it is much faster. There are several hook manufacturers making a scud hook. All of these will give the pattern a nice arch. Tie several with bends and several without. I find the straight hooks to be more effective. This may be because the scuds straighten out when they swim.
Hook: Mustad 3906B or Dai-Riki 075
Size: 8 to 20
Tail: Fine rubber
Shell: Pearlescent wing material cut into strips.
Ribbing: Fine gold wire.
Body: Dubbing of choice.
Step 1: Tie in rubber legs as a tail, or feelers in this case, equal to the overall length of the hook. Next tie in the gold wire and pearlescent material. Leave them extended off the back of the hook. (Note: This pattern should start well below the bend of the hook.)
Step 2: Apply dubbing or yarn and wrap an egg shape onto the hook being sure to leave enough space to tie off all of the materials. One of the hardest things to master on this pattern is keeping the head small, or smaller than the rest of the fly. If you are using a yarn, only use on or two wraps to hold it down. Your ribbing will secure the body.
Step 3: Pull the pearl wing material over the top to form the shell and tie down, again only using a few wraps. Then rib the fly with six or seven wraps. Tie off the wire. Only use as many wraps forming the head as it takes to cover the wire end. Whip finish and cement.
Step 4: Use a small strip of Velcro to pull out the legs. Once they are long enough, usually equal to the hook gap, pull them forward towards the eye of the hook.